This invention relates to computer systems for monitoring and interpreting the status of various underwater diving-related parameters, such as the status of compressed air supplies for scuba (self contained underwater breathing apparatus) divers, and in particular, relates to systems capable of receiving diver input for selected parameters, and determining specified dive characteristics in view of the diver-specific input values.
A recurring concern of users of scuba gear is how long a given air supply will last. To ensure an adequate air supply, the diver may cut his or her dive short, returning to the surface with a large excess of breathable air. Erring too far on the side of caution, however, wastes time and resources, and restricts diving flexibility. To help solve this problem, dive computers were created to assist divers maximizing the length of their dive time without incurring substantial additional risk.
Conventional dive computers calculate a diver's air consumption, measure the remaining air supply, and then determine the time a diver may safely remain at his current depth. These computers display the time remaining based on the diver reaching the surface either just prior to the complete exhaustion of his air supply or with some fixed safety margin (300 PSI, for example).
Fixed safety margins, however, are unresponsive to various diver needs. For example, the diver may require an extra air reserve in order to facilitate a long swim to shore or to a boat. Also, the diver may want an extra supply of air in case of an emergency. Furthermore, a diver may simply prefer safety margins different from those prescribed by the dive equipment manufacturers. In addition, there are other dive-related parameters which influence air consumption, or general diver performance, including the age, gender, physical condition of the diver, as well as the number, depth and duration of dives previously made by the diver.
There is a need, therefore, for an instrument that determines a safe diving or air reserve period based on both current dive conditions and the diver's personal safety margin preferences, as well as the diver's particular physical profile.
It is a main object of the invention to provide a dive computer designed to guide a diver to the surface with a diver-specified air reserve remaining in a compressed air supply at the completion of the dive.
Another object of the invention is to provide a dive computer which receives a variety of diver inputs to both more accurately monitor diver performance, and to provide additional information to the diver regarding dive-related conditions.
Yet another object of the invention is to enhance the accuracy of such a dive computer by basing dive projections on the history of previous dives and by repetitively recalculating the safe diving period during a current dive.